1. Field of the Invention
The present invention relates to an image forming apparatus and an ejection state determination method, and more particularly to image formation technology and liquid ejection state determination technology, suitable for an inkjet recording apparatus which forms images of high quality on a recording medium by using ink containing a coloring material, and a treatment liquid.
2. Description of the Related Art
In the field of inkjet printing technology, methods which conjointly use an ink containing coloring material and a treatment liquid, in order to form images of high quality, are known. In the method using the treatment liquid, it is necessary to make the treatment liquid and the ink react reliably on the recording medium, and therefore, if the treatment liquid is not deposited or if there is deviation between the application positions (the deposition positions) of the ink and the treatment liquid, then the effect of the treatment liquid is not obtained sufficiently. In response to these problems, various technologies have been proposed with a view to determining the ejection of transparent treatment liquid (see Japanese Patent Application Publication Nos. 2000-168106, 2004-276314, and 2004-314362).
Japanese Patent Application Publication No. 2000-168106 discloses technology which uses an ejection test film as a device for testing the ejection state of a colorless transparent treatment liquid. Japanese Patent Application Publication No. 2004-276314 discloses technology for recording a test pattern by combining with another type of liquid, as technology for confirming the ejection from nozzles which eject liquid that is not readily visible. Japanese Patent Application Publication No. 2004-314362 discloses technology for detecting missing dots of liquid that is not readily visible, on the basis of the difference in the degree of scattering of the light occurring due to the microscopic surface state of the recording medium.
On the other hand, Japanese Patent Application Publication No. 2001-226618 discloses technology relating to ink having spectral absorption in the infrared region, and discloses a drying method where heating is performed by applying infrared light, after printing. Japanese Patent Application Publication No. 2002-146254 discloses technology for providing an invisible pattern made of an infrared absorbing material, with a view to design restrictions of a printed object or forgery prevention of same.
Japanese Patent Application Publication No. 2000-168106 discloses the method using the ejection test film which changes color due to the treatment liquid, as technology for determining the ejection state of the transparent treatment liquid, but it requires the use of a special medium for the purpose of test (i.e. the ejection test film). The method disclosed in Japanese Patent Application Publication No. 2004-276314 has a problem in that determination is instable, due to the circumstances of the combination with a different type of liquid. The method disclosed in Japanese Patent Application Publication No. 2004-314362 requires a detector which is capable of high-precision adjustment of the light path, and high-sensitivity determination.
Japanese Patent Application Publication No. 2001-226618 discloses technology which promotes drying by including the infrared absorbing material in the ink containing the coloring material, but it does not disclose technology relating to a transparent treatment liquid used in a two-liquid reaction system. Japanese Patent Application Publication No. 2002-146254 discloses the printing of the invisible pattern by including the infrared absorbing material in the ink, but it simply deals with the issue of providing the invisible pattern by means of the specific material, and it does not discuss the concept of using infrared absorption in the promotion of drying, the determination of the ejection state, or the like.